A Ribbon of Life Through the Concrete of Houston

Room for the River: What the River Scientist Had to Say

November 25, 2014

Updated Saturday, Nov. 29, 2014, with a link to the video of the lecture by Mathias Kondolf.

More than 100 people gathered last Friday evening to hear Mathias Kondolf speak about rivers, river restoration, and the state of Buffalo Bayou at the Assembly Hall of St. Theresa Memorial Park Catholic Church.

Kondolf is a professor at the University of California at Berkeley, a world-renowned river scientist, and a leading critic of the destructive and often-failing methods proposed for a $6 million “erosion control” and “bank stabilization” project on Buffalo Bayou. He spoke for nearly two hours to a crowd that included people on all sides of a controversial project to bulldoze the riparian forest and dredge and channelize nearly 1.5 miles of one of the last natural stretches of the bayou in the city.

The project, known as the Memorial Park Demonstration Project, was conceived by the Bayou Preservation Association, which actively promotes the plan. The Army Corps of Engineers is considering whether to issue a permit to the Harris County Flood Control District for the project.

Riparian forest or buffer, also called a riparian zone, consists of specially adapted trees and plants along the edge of a waterway. Among the many important functions of riparian zones are protecting the land from erosion, filtering pollution, cleansing the water, slowing flood water, and providing wildlife and human habitat.

Kondolf had spent hours inspecting the bayou in the rain earlier in the day. The project area is bounded entirely on the south by the River Oaks Country Club golf course, which is currently being renovated. The north bank of the project is our public Memorial Park, along with the Hogg Bird Sanctuary and some private property. Taxpayers are contributing $4 million to this project.

Rivers Are Naturally Dynamic

Kondolf spoke about the natural dynamics of rivers and gave numerous examples from around the world. “The most ecologically diverse, the most valuable ecosystems are those that are dynamic,” he said.

Because of the importance of letting the river move around, the concept of l’espace de liberté or “room for the river” has become one of the central ideas of river restoration and management in Europe, Japan, and in places like Washington state, where it’s called a “channel migration zone.”

“The basic idea is that you give the river some room,” he said. “And you don’t build right up to the edge. Because when you do that you inevitably create conflicts with the river. You give the river some place where it’s okay to erode, where it’s okay to deposit, it’s okay to be a river.”

Kondolf showed several examples of projects similar to the one proposed for Buffalo Bayou that had failed and washed out. Proponents of a failed project in Deep Run, Maryland, for example, “never did an analysis to figure out” where problems “were coming from.” (It turned out to be construction of a shopping center upstream.) The authorities removed a “nice riparian forest” and created perfectly symmetrical meander bends that increased the velocity of the river resulting in the river cutting a new channel.

“Any time that you go in and remove existing riparian forest to build some idealized form, you have to be aware that since [the river] is no longer slowed down when it goes overbank … it is going to find its own way.”

We’ll have more later on Kondolf’s highly informative lecture and the lively discussion that followed. Basically he said that the proposed project is unnecessary, likely to fail, and that in this historic natural area there is room for this river to move. So we should let the bayou be a bayou.

The good Dr. Knows his stuff! If the HCFCD really were open to comments they would listen to what the leading fluvial geomorphologist had to say about not destroying the riparian zone along Buffalo Bayou.